Anti-fuse one-time programmable memory cell and related array structure

Abstract

An one-time programmable memory cell includes: an upper electrode; an insulating layer beneath the upper electrode; and a lower electrode with electrical field enhancement structure beneath the insulating layer, wherein the electrical field enhancement structure has a least one tip portion. The one-time programmable memory cell also includes a shallow trench isolation region, disposed adjacent to the insulating layer and the lower electrode, wherein the electrical field enhancement structure is surrounded by the shallow trench isolation region and the upper electrode partially covers the shallow trench isolation region.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of U.S. Provisional Application No. 62 / 940,252, filed on Nov. 26, 2019. The entire contents of the related application are incorporated herein by reference.BACKGROUND OF THE INVENTION1. Field of the Invention[0002]The present invention relates anti-fuse elements, and more particularly, to one-time programmable (OTP) type anti-fuse devices with electrical field enhancement structures.2. Description of the Prior Art[0003]An anti-fuse element is a semiconductor device that changes its state from non-conductive to conductive. When an anti-fuse element is “fused,” its open circuit state becomes shorted and conduction across electrodes of anti-fuse element becomes possible. Typically, the electrodes across the anti-fuse element is conducted by applying a sufficiently high voltage difference between electrodes of the anti-fuse element, thereby, breakdown the insulating layer (such as silicon dioxide) which loc...

AI Technical Summary

Benefits of technology

The present invention provides a novel anti-fuse one-time programmable memory (OTP) cell and an array structure thereof. The invention uses electrical field enhancement to improve data reliability in the OTP memory cell. By enhancing the local electrical field, the breakdown position of the insulting layer can be better controlled, resulting in more effective programming of the memory cells.

Problems solved by technology

The existing anti-fuse memory technology has several problems, one of which is the wide-variation of conductivity of the programmed anti-fuse elements.

This problem is mainly caused by the fact that the breakdown position of the insulting layer could vary based on many factors.

As the breakdown position could be literally uncertain, it will bring the uncertainty of the conducted path and thus unfavorable effects to the reliability of the programmed information that stored in the OTP memory cell.

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